<template>
  <div class="cart">
    <h4>全部商品</h4>
    <div class="cart-main">
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价（元）</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <div class="cart-body">
        <ul class="cart-list" v-for="cart in cartInfoList" :key="cart.id">
          <li class="cart-list-con1">
            <input
              type="checkbox"
              name="chk_list"
              :checked="cart.isChecked"
              @change="updateChecked(cart, $event.target.checked)"
            />
          </li>
          <li class="cart-list-con2">
            <img :src="cart.imgUrl" />
            <div class="item-msg">{{cart.skuName}}</div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{cart.skuPrice}}.00</span>
          </li>
          <li class="cart-list-con5">
            <a href="javascript:void(0)" class="mins" @click="handler('min', -1, cart)">-</a>
            <input
              autocomplete="off"
              type="text"
              :value="cart.skuNum"
              minnum="1"
              class="itxt"
              @change="handler('change',$event.target.value*1, cart)"
            />
            <a href="javascript:void(0)" class="plus" @click="handler('add', 1, cart)">+</a>
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{cart.skuNum * cart.skuPrice}}.00</span>
          </li>
          <li class="cart-list-con7">
            <a class="sindelet" @click="deleteCartById(cart)">删除</a>
            <br />
            <a>移到收藏</a>
          </li>
        </ul>
      </div>
    </div>
    <div class="cart-tool">
      <div class="select-all">
        <input
          class="chooseAll"
          type="checkbox"
          :checked="isAllChecked && cartInfoList.length > 0"
          @change="updateAllCartChecked"
        />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="deleteAllCheckedCart">删除选中的商品</a>
        <a href="#none">移到我的关注</a>
        <a href="#none">清除下柜商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">
          已选择
          <span>0</span>件商品
        </div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{totalPrice}}.00</i>
        </div>
        <div class="sumbtn">
          <router-link class="sum-btn" to="/trade">结算</router-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { mapGetters } from 'vuex'
// 引入lodash实现节流（这里是按需引入的）
import throttle from 'lodash/throttle'

export default {
  name: 'ShopCart',
  methods: {
    getData () {
      this.$store.dispatch('getCartList')
    },
    // 修改某个产品的个数(使用一下节流)
    handler: throttle(async function (type, disNum, cart) {
      // type: 为了区分是加还是减还是chagne
      // disNum：input最终的个数（不是变化量）
      // cart: 点击的是哪个产品，因为要拿到该产品的skuId
      // 向服务器发请求，修改数量
      switch (type) {
        case 'add':
          disNum = 1
          break
        case 'min':
          disNum = cart.skuNum > 1 ? -1 : 0
          break
        case 'change':
          if (isNaN(disNum) || disNum < 1) {
            disNum = 0
          } else {
            disNum = parseInt(disNum) - cart.skuNum
          }
      }

      try {
        // 代表的是修改成功，派发action
        await this.$store.dispatch('addOrUpdateShopCart', { skuId: cart.skuId, skuNum: disNum })
        // 再次发送请求获取服务器最新的数据
        this.getData()
      } catch (error) {
        // 若修改失败则
      }
    }, 1000),

    // 删除某个产品的操作
    async deleteCartById (cart) {
      try {
        await this.$store.dispatch('deleteCartListById', cart.skuId)
        this.getData()
      } catch (error) {
        alert('删除失败')
      }
    },

    // 修改商品的选中状态
    async updateChecked (cart, isChecked) {
      try {
        let Checked = isChecked ? 1 : 0
        await this.$store.dispatch('updateCheckedById', { skuId: cart.skuId, isChecked: Checked })
        // 再次获取服务器数据
        this.getData()
      } catch (error) {
        alert('操作失败')
      }
    },

    // 删除选中的所有商品
    async deleteAllCheckedCart () {
      try {
        // 派发一个action
        await this.$store.dispatch('deleteAllCheckedCart')
        // 若成功了就再次请求服务器获取数据
        this.getData()
      } catch (error) {
        alert('清除失败')
      }
    },

    // 全选勾选框的全选与取消全选
    async updateAllCartChecked (event) {
      try {
        let isChecked = event.target.checked ? 1 : 0
        // 派发action
        await this.$store.dispatch('updateAllCartChecked', isChecked)
        // 再次请求服务器数据
        this.getData()
      } catch (error) {
        alert('全选/取消失败')
      }
    }
  },

  mounted () {
    this.getData()
  },

  computed: {
    ...mapGetters(['cartList']),
    // 捞想要的数据
    cartInfoList () {
      return this.cartList.cartInfoList || []
    },
    // 计算产品的总价
    totalPrice () {
      let sum = 0
      this.cartInfoList.forEach(item => {
        if (item.isChecked) {
          sum += item.skuNum * item.skuPrice
        }
      });
      return sum
    },
    // 判断底部的复选框是否勾选（全部商品选中则勾选）
    isAllChecked () {
      // 判断数组中的每个元素是否都满足给定的条件，都满足则返回true，不满足则返回false
      return this.cartInfoList.every(item => item.isChecked == 1)
    }
  }
}
</script>

<style lang="less" scoped>
.cart {
  a {
    text-decoration: none;
    cursor: pointer;
  }
  width: 1200px;
  margin: 0 auto;

  h4 {
    margin: 9px 0;
    font-size: 14px;
    line-height: 21px;
  }

  .cart-main {
    .cart-th {
      background: #f5f5f5;
      border: 1px solid #ddd;
      padding: 10px;
      overflow: hidden;

      & > div {
        float: left;
      }

      .cart-th1 {
        width: 25%;

        input {
          vertical-align: middle;
        }

        span {
          vertical-align: middle;
        }
      }

      .cart-th2 {
        width: 25%;
      }

      .cart-th3,
      .cart-th4,
      .cart-th5,
      .cart-th6 {
        width: 12.5%;
      }
    }

    .cart-body {
      margin: 15px 0;
      border: 1px solid #ddd;

      .cart-list {
        padding: 10px;
        border-bottom: 1px solid #ddd;
        overflow: hidden;

        & > li {
          float: left;
        }

        .cart-list-con1 {
          width: 15%;
        }

        .cart-list-con2 {
          width: 35%;

          img {
            width: 82px;
            height: 82px;
            float: left;
          }

          .item-msg {
            float: left;
            width: 150px;
            margin: 0 10px;
            line-height: 18px;
          }
        }

        .cart-list-con4 {
          width: 10%;
        }

        .cart-list-con5 {
          width: 17%;

          .mins {
            border: 1px solid #ddd;
            border-right: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }

          input {
            border: 1px solid #ddd;
            width: 40px;
            height: 33px;
            float: left;
            text-align: center;
            font-size: 14px;
          }

          .plus {
            border: 1px solid #ddd;
            border-left: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }
        }

        .cart-list-con6 {
          width: 10%;

          .sum {
            font-size: 16px;
          }
        }

        .cart-list-con7 {
          width: 13%;

          a {
            color: #666;
          }
        }
      }
    }
  }

  .cart-tool {
    overflow: hidden;
    border: 1px solid #ddd;

    .select-all {
      padding: 10px;
      overflow: hidden;
      float: left;

      span {
        vertical-align: middle;
      }

      input {
        vertical-align: middle;
      }
    }

    .option {
      padding: 10px;
      overflow: hidden;
      float: left;

      a {
        float: left;
        padding: 0 10px;
        color: #666;
      }
    }

    .money-box {
      float: right;

      .chosed {
        line-height: 26px;
        float: left;
        padding: 0 10px;
      }

      .sumprice {
        width: 200px;
        line-height: 22px;
        float: left;
        padding: 0 10px;

        .summoney {
          color: #c81623;
          font-size: 16px;
        }
      }

      .sumbtn {
        float: right;

        a {
          display: block;
          position: relative;
          width: 96px;
          height: 52px;
          line-height: 52px;
          color: #fff;
          text-align: center;
          font-size: 18px;
          font-family: 'Microsoft YaHei';
          background: #e1251b;
          overflow: hidden;
        }
      }
    }
  }
}
</style>